During the last three years of the research, we have established an estrogen independent endometrial cancer cell lines and from one line, a highly metastatic endometrial cancer strain, mEIIL.Studies of the line have shown that it has gained higher expression of nidogen, a protein specific to the basement membranes. Also the line expressed more c-erbB-2 product than the mother line. Injecting the cells intraperitoneally to nude mice produced retroperitoneal node dissemination and frequent liver metastasis. Transfection and expression of normal human estrogen receptor cDNA into the mEIIL cells reduced the metastatic activity of the mEIIL 75%.